What does 'colerize' mean ?

[MircoPB]

Well, maybe, its a very dump question, but i don't know what the colorize-Option in the Hue/Saturation Adjustment Layer means.
Well, ok, i know the differents, but i cannot explain in my own words, what is happened there.
I Just try to click, to find the best option, but i want to UNDERSTAND what i do.
Who can help me ?

best regards Mirco

[Phil_The_Rodent]

Colourize adds Hue to a Greyscale selection. If the selection is coloured, PS will Greyscale it and then add colour. It's like going from Greyscale to Doutone colour mode, but where Duotone will add functionality to the curve of how the colour is applied, colourize adds functionality to the Hue and Saturation of how the colour is applied.